Differential Expression of Paired Related Homeobox 1 in Gingival Tissues and Its Association With Site-Specific Wound...

Gingival wound healing exhibits site-specific variability, with more rapid healing observed at the alveolar ridge than at the palatal region. Cells expressing paired related homeobox 1 (PRRX1) have been identified in the periodontal ligament of both mice and humans. This study aimed to evaluate PRRX1 expression in normal gingival tissues, compare wound-healing rates across distinct gingival sites, and examine the potential role of PRRX1 in gingival wound repair.

A rat model was utilized to assess PRRX1 expression in normal gingival tissues through immunohistochemical analysis. Two millimeter punch wounds were created at the alveolar crest and palatal sites in 12 rats, with contralateral regions serving as uninjured controls. The animals were euthanized on postoperative days 0, 3, 6, and 9. Comparative analyses were conducted to assess wound-healing rates and PRRX1 expression during the healing period.

Wound closure progressed more rapidly at the alveolar crest than at the palate. By postoperative day 6, the alveolar crest wounds were nearly healed, whereas the palatal wounds demonstrated delayed epithelial and connective tissue repair. Histologic examination indicated enhanced collagen fiber proliferation at the alveolar crest. Immunohistochemical findings revealed elevated PRRX1 expression at both wound sites during the healing phase, with no statistically significant difference between sites (P>0.05).

Healing of gingival wounds proceeded more rapidly at the alveolar crest than at the palatal region, accompanied by upregulated PRRX1 expression at both sites during active repair. These findings indicate that PRRX1 contributes to gingival wound-healing processes and may represent a potential therapeutic target for promoting periodontal tissue regeneration.